public class num572 {
    public boolean isSubtree(TreeNode root, TreeNode subRoot) {
        if(root == null && subRoot == null){
            return true;
        }
        if(root == null || subRoot == null){
            return false;
        }
        return isSameTree(root,subRoot) || isSubtree(root.left,subRoot) || isSubtree(root.right,subRoot);
    }
    public boolean isSameTree(TreeNode p, TreeNode q) {
        if(p == null && q == null){
            return true;
        }
        if(p == null || q == null){
            return false;
        }
        return p.val == q.val && isSameTree(p.left,q.left) && isSameTree(p.right,q.right);
    }
}
